1. Field of the Invention
The invention relates to a feeding connector for feeding electric power from a vehicle to an external power receiving device, a method for identifying the connector, a system for identifying the connector, and a feeding system using the connector. More particularly, the invention relates to a feeding connector that can be fitted to a connecting portion (e.g., a vehicle inlet) to which a charging connector that connects the vehicle with an external feeding device is fitted when an electric storage device installed on the vehicle (e.g., a plug-in hybrid vehicle (PHV) or an electric vehicle (EV)) is charged with electric power from the feeding device. The invention also relates to a method for identifying such a connector, a system for identifying the connector, and a feeding system using the connector.
2. Description of Related Art
An electrically powered vehicle is installed with an electric storage device (e.g., a secondary battery or a capacitor), and is adapted to run, using driving force generated from a driving power source (e.g., a motor) that is driven with electric power stored in the electric storage device. Examples of the electrically powered vehicle include an electric vehicle (EV), a hybrid vehicle (HV), and so forth.
In connection with the electrically powered vehicle, a technology of charging the electric storage device installed on the electrically powered vehicle, by means of a commercial power supply (e.g., a source of a relatively low voltage of 100V or 200V) that supplies electric power to each home, for example, has already been developed. In the following description, the vehicle in which the electric storage device (e.g., a battery) installed on the vehicle can be charged by means of an external power supply of the vehicle may be called “plug-in vehicle” when appropriate.
In the hybrid vehicle (HV), a motor that normally functions as a driving power source may be driven as a generator, by an internal combustion engine installed on the HV or through regenerative braking, for example, so as to charge the electric storage device installed on the HV. The electric storage device may also be charged by means of the external power supply as described above. The HV of this type may also be called “plug-in hybrid vehicle (PHV)”.
In the meantime, it has been proposed to supply electric power from the electric storage device installed on the electrically powered vehicle as described above, to an external power receiving device (e.g., a power supply or an electric load), in order to make efficient use of electric power from an environmental viewpoint, or alleviate power shortage in times of disaster, for example. In other words, it has been proposed to use the electric storage device installed on the electrically powered vehicle, as a feeding device for feeding electric power to the external power receiving device.
In this case, a feeding mechanism for supplying electric power from the electric storage device installed on the electrically powered vehicle to the external power receiving device may be provided separately from or independently of a charging mechanism for charging the storage device by supplying electric power from an external feeding device (e.g., a commercial power supply) to the storage device installed on the electrically powered vehicle. However, providing the feeding mechanism separately from the charging mechanism may incur various problems, such as increase in the size of the vehicle, increase in complexity of the feeding/charging mechanism, and increase in the manufacturing cost of the vehicle.
Thus, in the technical field concerned, various technologies have been proposed which permit a single mechanism to feed electric power from the vehicle to the external power receiving device and also charge electric power from the external feeding device into the storage device installed on the vehicle, by switching the mechanism between the two modes of operation.
For example, an electric power management system that permits electric power to be transmitted between a battery of an electric vehicle and a house is described in, for example, Japanese Patent Application Publication No. 2001-008380 (JP 2001-008380 A). In this system, a house-side main controller determines whether a charge mode or a discharge mode is to be established, and a charge/discharge control signal is transmitted from a house-side charge/discharge controller to a vehicle-side battery controller via a communications antenna, while charge control or discharge control is performed in the vehicle, based on the charge/discharge control signal received via the communications antenna. However, additional provision of the communications antenna results in increase in the cost of the system and increase in complexity of a control system.
In the meantime, as one of standards for electric vehicles having on-board batteries that can be charged with electric power from houses, the Society of Automotive Engineers (SAE) in the U.S. has established “SAE Electric Vehicle Conductive Charge Coupler” (“SAE Electric Vehicle Conductive Charge Coupler” (US), SAE Standards, SAE international, November 2001). In Japan, too, “General Requirements for Electric Vehicle Conductive Charging System” (“General Requirement for Electric Vehicle Conductive Charging System”, Japan Electric Vehicle Association Standard, Mar. 29, 2001) is established.
In the “SAE Electric Vehicle Conductive Charge Coupler” (US), SAE Standards, SAE international, November 2001, and the “General Requirements for Electric Vehicle Conductive Charging System”, Japan Electric Vehicle Association Standard, Mar. 29, 2001, standards concerning a control pilot are set. The control pilot is defined as a control line that connects a control circuit of EVSE (Electric Vehicle Supply Equipment) that supplies electric power from house or indoor wiring to a vehicle, with a ground portion of the vehicle, via a vehicle-side control circuit. In operation, a connecting condition of a charging cable, whether or not electric power can be supplied from the power supply to the vehicle, the rated current of the EVSE, etc. are determined, based on a CPLT (Control Pilot Line Transmission) signal (pilot signal) transmitted via the control line.
Thus, in a vehicle charge/discharge system capable of charging the electric storage device installed on the vehicle with electric power from a power supply outside the vehicle and also capable of feeding electric power from the storage device to a power supply or electric load outside the vehicle, it has been proposed to cause a signal generating circuit provided the charge/discharge system to generate a control signal (CPLT signal) from which it can be determined whether a power cable connected to the vehicle is a charging cable or a feeding cable, and cause a control device installed on the vehicle to control a power conversion device in either of a charging mode and a feeding mode, according to the control signal transmitted from the signal generating circuit (see, for example, Japanese Patent Application Publication No. 2010-035277 (JP 2010-035277 A)).
In order to determine which of the charging mode and the feeding mode is to be established based on the CPLT signal as described above, the signal generating circuit is required to generate the CPLT signal in both of the charging mode and the feeding mode. However, according to the standard concerning the control pilot as described above, electric power used for generating the CPLT signal is not supplied from the vehicle side. Consequently, the signal generating circuit provided in the charge/discharge system needs to be additionally provided with a power supply, such as an internal battery, or supply of electric power from the outside. However, the additional provision of the power supply for the signal generation circuit results in increase in the cost of the system and increase in complexity of the control device.
As described above, in the technical field concerned, there exists a continuing demand for a technology with which a system that permits electric power to be transmitted between the vehicle and the exterior thereof is able to determine whether to operate in the charging mode or the feeding mode, without substantially suffering from inconveniences, such as increases in the size, complexity, and cost of the system, for example.